在SaaS中使用原生XML数据库

多租户数据存储是软件即服务（SaaS）的重要研究点之一。现有的解决方案大都是基于关系数据库的模式映射技术,然而理想的SaaS多租户数据库并没有产生。文中从SaaS的web特性、数据存储存储灵活性和分布式特性三个方面讨论了在SaaS中使用原生XML数据库（NXD）的可能性,并且给出了等价于私有表方法的多租户数据XML存储结构。与此同时依据此XML结构进行了相关的实验,结果表明NXD作为理想的web中XML数据存储方式可以成为多租户数据存储的一种解决方案,并且能够有效地支持SaaS的web特性、数据存储灵活性等特点。     

在SaaS中使用原生XML数据库

多租户数据存储是软件即服务(SaaS)的重要研究点之一.现有的解决方案大都是基于关系数据库的模式映射技术,然而理想的SaaS多租户数据库并没有产生.文中从SaaS的web特性、数据存储存储灵活性和分布式特性三个方面讨论了在SaaS中使用原生XML数据库(NXD)的可能性,并且给出了等价于私有表方法的多租户数据XML存储结构.与此同时依据此XML结构进行了相关的实验,结果表明NXD作为理想的web中XML数据存储方式可以成为多租户数据存储 的一种解决方案,并且能够有效地支持SaaS的web特性、数据存储灵活性等特点.     

一种基于云计算的SaaS组装方法研究

根据基于云计算的SaaS(Software as a Service)软件的集成性、可配置性和定制性(简称IIC)所面临的问题.提出一种基于云计算的SaaS组装和质量方法:首先建立一种SaaS寻址方法和组装中断方法,以保证SaaS组装连续性和确定性;并根据寻址和中断情况建一种适合SaaS的相似度计算方法,以满足整个SaaS组装流程的精确性.其次根据SaaS的寻址组装和中断的情况,从Web服务质量、地址数量和分布、可用性、资源共享度、互操作性和ICC等角度建立SaaS组装质量模型,即QoSaaS(Quarry of SaaS).第三,在寻址中断支持和QoSaaS驱动下,构建一种SaaS组装算法.最后在Amazon下以一个SaaS销售软件生成为例进行分析,并给出一组数据验证表明该方法的可行性和有效性.     

Providing Software as a Service: a design decision(s) model

We examine how Software as a Service (SaaS) providers make different design decisions using a theoretical model. We consider two non-functional attributes: modularity of the software architecture and the architectural performance of the software. We model the relationship of these two attributes with factors such as user preferences, user demand, and the price of the service. In a significant departure from traditional models of IS product development, we considered marginal cost and maintenance cost of providing SaaS service to recognize that the SaaS service has characteristics of both a product and a service. We show how to find the optimal values of design attributes that maximize SaaS provider’s profits, taking into account relevant factors such as user preferences, user demand and service price. Our research provides one of the first analytical models of optimal design decision making by SaaS providers. We use the model to further show how the SaaS providers should adjust the service design in response to changes in user preferences, associated costs and other relevant factors.     

管理软件领域新动态之财务共享

随着近年来企业服务定位的转变,财务共享服务逐渐在大型集团企业中兴起,特别是在国有大中型企业中应用越来越多,这与国家政策导向有着紧密的关系。作为管理软件应用一线从业者,有机会发现管理软件领域应用的最新动态,亲历业务实践一线,获取第一手资讯。为此笔者参考近年来权威行业分析报告,对企业财务共享的概念、管理模式特点、适合实施的企业对象、实施业务内容等进行了概括性描述,并希望以案例剖析的方式,全面展示财务共享变革带给企业的方方面面的改变。诸如管理模式、业务流程再造、管理方式方法等方面与传统集团管理控制模式的不同。此外,也对中国市场上主流管理软件产品的变革提出了初步的建议,希望能为推动管理软件领域的发展助力。     

基于代价感知的云任务处理策略

绿色云计算旨在保证服务质量的前提下,最大限度地降低云服务成本．针对这一问题,提出一种兼顾云数据中心高性能和低成本的策略,通过虚拟机动态迁移等技术进行云任务聚合,关闭空闲的节点以最小化能量消耗,同时考虑虚拟机迁移性能,以此保证任务的服务质量．实验结果表明,代价感知的策略可以减少打开节点的个数,兼顾迁移能耗和迁移延迟,在节能的前提下使服务质量得到保证．     

一种成本相关的云提供商数据可靠性保证算法

数据可靠性保证和容灾成本控制对云提供商而言是一个相互矛盾的问题.在分析已有数据保障机制的基础上,设计了一个基于多个云平台的分布式富云容灾模型,利用富云容灾系统,私有云提供商可以借用其他云平台的虚拟资源对自身数据进行冗余备份.为了减少数据传输的响应时间,富云容灾模型通过设置多个地理位置隔离的富云代理实现云平台用户任务的分配,减少私有云平台的工作负荷.针对富云容灾系统的成本优化和数据可靠性保证问题,提出了一种成本相关的云计算服务数据可靠性保证算法CAHRPA.该算法根据数据传输带宽和容灾费用在多个云平台中动态选择数据副本的存放位置,从而以一种成本优化的方式为云提供商提供数据容灾方案.实验结果表明,CAHRPA 能够在保证数据可靠性的同时,实现一种成本更低的数据容灾策略.     

Composition as a Service

Understanding reusable software and assets within and among multiple organizations' system infrastructures can be challenging. IT systems might be widely distributed, and interconnections can be complicated. Ever-evolving computing technologies reduce an organization's in-house expertise for reusing software, even when leveraging software systems within its own firewalls. As such, the on-demand integration of software and capabilities might benefit from an outsourcing paradigm — described here as composition as a service.     

一种基于软件+服务平台的软件架构模式

本文在介绍软件+服务平台的概念的基础上,设计了一种基于软件+服务平台的软件架构模式,并对其核心组件进行了说明,最后通过分析该架构的使用效果,从而说明了该架构具有较好的应用前景.     

软件服务外包人才培养

分析了软件服务外包人才培养的特点和存在的问题,提出按校企协同人才培养模型培养软件服务外包人才,分析了校企合作类型,强调实践能力培养,提出三线并举的实践能力培养体系和岗位综合实践能力培养措施。     

Managing Applications as a Software Portfolio

Abstract

As demand grows faster than resources, MIS departments must change the way they allocate scarce resources to get work done. The concept of portfolio management provides a basis for decision making by optimizing MIS resources to meet the demands of end users as well as the long-term needs of an organization.     

Managing Applications as a Software Portfolio

As demand grows faster than resources, MIS departments must change the way they allocate scarce resources to get work done. The concept of portfolio management provides a basis for decision making by optimizing MIS resources to meet the demands of end users as well as the long-term needs of an organization.     

迈向管理服务化

Internet上越来越多的应用都具有Web风格,Web本身正逐步成为Internet上各类应用的运行平台,这种现象可称为"Web平台化","Web平台化"为信息技术的发展带来机遇和挑战。文章立足于探讨"Web平台化"所面临的关键技术挑战之一,即Web管理。首先从Web的特征出发,总结其对Web管理的要求;其次提出将"管理服务化"作为Web管理的解决方案,并指出"管理服务化"面临的技术挑战;最后以PKUAS支持的面向服务的管理为例展示"管理服务化"的可行性。     

Software engineering as a scientific and engineering discipline

A new interpretation of software engineering from scientific, engineering, and practical standpoints is proposed. Software engineering is defined as a successor of programming and computer science, namely, its management theory. Features and attributes of software engineering as an original discipline are founded. The structure, content, and concepts of this discipline and its basic elements are presented. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 19–28, May–June 2008.     

Financial Modeling and Prediction as a Service

This paper describes our proposal for Quality of Service (QoS) for Financial Modeling and Prediction as a Service (FMPaaS), since a majority of papers does not focus on SaaS level. We focus on two factors for delivering successful QoS, which are performance and accuracy for FMPaaS. The design process, theories and models behind the FMPaaS service have been explained. To support our FMPaaS service, two APIs have been developed to improve on performance and accuracy. Two major experiments have been illustrated and results show that each API processing can be completed in 2.12 seconds and 100,000 simulations can be completed in an acceptable period of time. Accuracy tests have been performed while using Facebook as an example. Three points of comparisons between actual and predicted prices have been undertaken. Results support accuracy since results are between 93.72 % and 99.63 % for Facebook. Three case studies have been used and results can support the accuracy and validity of the high level of accuracy offered by FMPaaS.     

一个软件服务协同中信任评估模型的设计

基于Internet的Web应用系统逐步表现为由多个软件服务组成的软件服务协同系统,面向开放、动态和多变的应用环境,软件服务之间的相互信任对软件服务个体和应用系统的安全保障与可靠运行均具有重要的意义.首先给出一个基于Agent的软件服务协同模型,随后针对该软件服务协同模型提出一个用于度量软件服务间信任关系的信任评估模型.信任被抽象成一个由信任评估主体对客体的主观期望和客观经验共同作用的函数,模型还提供了一个合理的方法用于综合直接经验和第三方推荐经验.与几个现有的工作相比,设计了较完整的信任评估模型,并强调其合理性和可操作性.信任评估模型可为软件服务之间的协同与安全决策提供依据.     

一个软件服务协同中的信任管理框架设计

Internet-based Web application systems are gradually built as software service coordination systems. In an open, dynamic and collaborative application environment, traditional methods assumed with closeness, centralization and independence are not able to cope with these security problems efficiently. Trust management is a new method for dealing with security issues of open, distributed network application system. However, the traditional policy-based trust management systems have some shortcomings, i.e. complex in policy making, unable to deal with negative se-curity credentials, etc. So, we design a trust management framework in combination with subjective trust model for software service coordination and security decision in Internet environment. This trust management framework has characteristics of operability, reasonability, and flexibility in policy setting.